Dual purpose lubricating compositions

ABSTRACT

This invention concerns dual-purpose packing compositions compatible with synthetic and natural lubricating oils comprising from about 30 to 50 parts by weight of a microcrystalline wax having a melting point about 50*-75* C. admixed with about 70 to 50 parts by weight of an aliphatic ester component derived from the esterification of aliphatic alcohols, diols and polyols or their ethers by aliphatic mono- or dicarboxylic acids. The packing compositions can contain from about 0.5 to 5 parts by weight of one or more extreme pressure or load bearing additives.

O United States Patent [151 3,640,858 Harr 1 1 Feb. 8, 1972 [54] DUALPURPOSE LUBRICATING 3,206,405 9/1965 Hepplewhite et a1. ..252/56 SCOMPOSITIONS 3,242,075 3/1966 Hunter ..252/59 3,252,909 5/1966 Jenks....252/56 S [72] Inventor: Stephen J. Han, Fishklll, N.Y. 3,468,701 9/1969 Hughes ..252/56 S [73] Assignee: Texaco Inc., New York, N.Y.FOREIGN PATENTS OR APPLICATIONS [22] 1968 749,391 5/1956 Great Britain..252/56 s [21] Appl. No.: 775,917

Primary Examiner-Daniel E. Wyman Assistant Examiner-l. Vaughn [52] US.CL ..252/49.8, 252/56 D, 252/56 S, A"0mey K Kavanagh and Thomas whaley252/59 [51] Int. Cl. ..Cm 7/44 57 ABSTRACT [58] Field of Search ..252/56S, 59, 56 D, 49.8 I

This invention concerns dual-purpose packing compositions [56]References Cited co npatible with synthetic and natural lubricating oilscomprising from about to parts by weight of a microcrystal- UNITEDSTATES PATENTS line wax having a melting point about 5075 C. admixedwith about to 50 parts by weight of an aliphatic ester component2,350,571 6/1944 Schrihng CI 3.1. derived from the esterification ofaliphatic alcohols, dials and 2,729,665 1/ 1956 Buckmann polyols ortheir ethers by aliphatic monoor dicarboxylic 2,782,166 2/1957Kolfenbach 61 al ..252/56 S acids The packing compositions can contain fabout 05 2,922,762 1/ 1960 Morway ..252/39 to 5 parts by weight of oneor more extreme pressure or load 2,944,973 7/1960 Langer et al. 252/56 Sbearing additives 3,105,400 10/1963 Goppelt ..252/56 S 3,115,422 12/1963Thomson ..252/56 S 12 Claims, No Drawings DUAL PURPOSELUBRICATING'COMPOSITIONS This invention concerns compositions useful forpacking and lubricating of turbine engine parts both during assembly andinitial operation.

More particularly, this invention relates to dual-purpose packingcompositions compatible with synthetic and naturally derived lubricatingoils and which are capable of lubricating turbine engines under initialstartup and breaking-in operating conditions.

Presently, thickened petroleum based jellies or thickened oils areemployed to temporarily hold turbine engine parts during assembly. Thesejellies and oils are troublesome to remove and are left on parts such asbearings or rollers with the expectation that they will merge with thelubricating oils during initial operation. Unfortunately, particularlyin the case of jet-type turbine engines where synthetic lubricating oilsare employed, the petroleum-based packing compounds do not readily mixwith the synthetic oils at startup temperatures which are below thoseachieved during engine warmup. Inasmuch as the normal engine lubricantis blocked from reaching critical parts during the time that elapsesbetween engine startup and engine warmup and inasmuch as thepetroleum-based packing compound does not satisfactorily lubricate theseparts, adequate lubrication is not achieved. This lag in lubrication hasresulted in premature failure of movable parts such as bearings androllers. In view of the inadequacies of presently available petroleumbased packing compositions, there is a need for improved packingcompositions which can be used in the assembly of turbine engine partsand provide for their adequate lubrication immediately upon startup andduring initial operation.

ideally, a dual purpose material is needed. The packing compound notonly would have a sufficiently high viscosity to hold the engine partsduring assembly but the composition must quickly and completely merge oncontact with turbine lubricating oils even at relatively lowtemperatures. This type of material would fill a real need in the art.

It is an object of this invention, among others, to provide adual-purpose packing composition which can be applied during theassembly of turbine engines and which will lubricate during the initialstages of engine operation. A more specific object of this invention isthe development of packing compositions which dissolve even atrelatively low temperatures upon contact with synthetic lubricating oilsand merge to form homogenous and stable lubricants.

A further object is the preparation of the above packing compositionswhich in conjunction with synthetic lubricating oils providesatisfactory lubrication of the engine during the critical period ofengine start-up to engine warmup during the run-in period which followsassembly and/or overhaul.

Additional objects will suggest themselves to the reader after a perusalof this invention.

The above objects are achieved by the formulation of a packingcomposition having two essential components present in the proportionsindicated:

a. From about 30 to 50 parts by weight of a petrolatum-type materialadmixed with,

b. From about 70 to 50 parts by weight of an aliphatic ester componentderived from the esterification of aliphatic alcohols, diols, polyolsand their ethers, by aliphatic monoor dicarboxylic acids.

While the above formulation represents a satisfactory dualpurposepacking composition and a distinct improvement over the art, as isfrequently the case, certain combinations of specific ingredientsprovide improved results and are less costly than the general class andare therefore preferred. In this instance, admixtures of petrolatum withan ester component (defined more fully below), and extreme pressure(E.P.) additives represent the preferred packing compositions of thisinvention. These preferred compositions compose an admixture of thefollowing components in the proportions indicated:

a. From about 35 to 45 parts by weight of petrolat b. From about 64 to43 parts by weight of an ester component selected from the groupconsisting of (l) the esters formed from dicarboxylic acids andaliphatic alcohols having one to eight carbon atoms and (2) the estersformed from monocarboxylic acids having from four to 12 carbon atoms andtetrols, and c. From about 0.5 to 5 parts by weight of one or moreextreme pressure or load bearing additives.

If, in addition to lubrication, ancillary properties are sought in thepacking composition the usual additives may be incorporated into thecomposition to replace up to a total of 5 parts by weight of either thepetrolatum and/or ester component. These additives include the usualcommercially available materials such as the following:

Oxidation and corrosion inhibitors such as penothiazine, orthothiazine,metathiazine, parathiazine, aromatic amines such as dioctyldiphenylaminephenyll-napthylamine, phenyllnapthylamine, quinizarin, alizarin,1,4-dihydroxyanthraquinone and sebacic acid. Other illustrativeadditives are viscosity and pour depressants such as the copolymers oftwo or more aliphatic esters of methacrylic acid having a molecularweight between 5,000 and 20,000 surfactants of the water-resistant typesuch as the quaternary ammonium salts of fatty acids, polygylcol ethers,metal alkyl sulfates and sulfonates may also be employed. Additionalclasses of additives as well as listings of specific additives may befound in the technical and patent literature.

In order that a better understanding of the invention be obtained thefollowing detailed description of the packing composition components anda process for preparing them is submitted.

A. Petrolatum-type material This is the generic term used throughoutthis application to describe those highly branched solid hydrocarbonmixtures derived from petroleum refining and which are in the form ofmicrocrystalline waxes having a melting point about 50-75 C. (l22-l67F). The major requirement of this material is that when admixed with theester component in the specified proportions it produces a packingcomposition meeting two requirements:

a. Compatibility with lubricating oils at temperatures below thoseproduced after engine wannup.

b. That the resultant composition have a worked penetration of between300-400 when measured using the ASTM D 217 60 stroke worked penetrationprocedure.

B. Ester component This term as used throughout this application refersto the aliphatic esters derived from esterifying aliphatic alcohols,diols, polyols and their ethers with monoand/or dicarboxylic acids. Theester components are all known compounds and can be purchased asarticles of commerce or prepared by conventional esterificationtechniques well known in the art. The aliphatic acids ordinarily containfrom three to 25 carbon atoms, preferably four to 12 carbon atoms. Thealcohol reactant ordinarily has from two to 20 carbon atoms preferablyfrom four to 12 carbon atoms while the polyol or diol can have fromthree to 20 carbon atoms, preferably from four to 12 carbon atoms.Illustrative esters are as follows: di-isooctyl azelate, di-Z-ethylhexylsebacate, di-Z-ethylhexyl azelate, di-2- ethyl hexyladipate, dilaurylazelate, di-sec-amyl sebacate, di- 2-(2' butoxyethoxy) ethylalkenylsuccinate, the di-ndecanoate of 1,4-butanediol, the dilaurate of1,4-hexanediol,

dioctanoate of l,5-pentanediol, the dilaurate of tetraethylene.

glycol, the dioctanoate of pentaethylene glycol, the trimethyol propanetriheptanoate, the trimethyol propane trioctanoate, the trimethyolpropane tripelargonate, pentaerythritol tetravalerate, pentaerythritolpelargonate, pentaerythritol butyrate, pentaerythritol caprylate,pentaerythritol heptanoate, pentaerythritol octanoate, pentaerythritolcaprylate. Mixtures of one or more of these esters including smallquantities of the free acids can also be used. The preferred esters areselected from the group consisting of:

a. Esters formed by the reaction of sebacic acid with aliphatic alcoholshaving from four to 12 carbon atoms and their mixtures.

b. Esters formed by the reaction of aliphatic acids withpentaerythritol, wherein the aliphatic acid contains from four to 12carbon atoms.

C. Extreme Pressure Additives As disclosed earlier, the preferred E. P.additive is tricresyl phosphate in concentrations of 0.5 to 3 percent byweight. However, satisfactory results are obtained where the sameconcentrations of other E. P. additives are employed. These additivesare generally organic compounds containing phosphorous and sulfur suchas the esters of phosphorous acids, organic phosphates and phosphitessuch as zinc dithiophosphate, neutral aromatic sulfur compounds,selenides, sulfurized long-chain olefins, phosphorous acid esters havingsulfurized radicals and heavy metal soaps such as lead naphthenate.

D. Process For Preparing Packing Compositions The process employed toprepare the packing compositions is simple to perform and requires noparticular equipment or precautions. The petrolatum-type component andester component are combined with any optional additives including E. P.additives. No particular order of addition is needed and standardlaboratory or plant mixing or blending equipment will suffice. Thecombined components and optional additives are stirred or agitated whileheating between about 175 to 250 F. until a homogenous mixture isproduced. Ordinarily this requires only a matter of minutes with to 15minutes being typical. Longer stirring and heating times are notdetrimental. After a homogenous mixture is obtained the source of heatand agitation are removed and the mixture is poured into the desiredcontainer and allowed to set. A period of several hours is usuallysufficient with 3 to 12 hours representing an average setting andcooling time depending upon the quantity of compound in the container.Upon setting, the packing composition has a consistency resembling thatof No. 1 grade grease (300375,ASTM D217 60 stroke worked penetration)and is sufficiently tacky to hold the turbine parts during assembly.

The following examples describe the preparation of dualpurpose packingcompositions and their evaluation.

EXAMPLE 1 Penetration ASTM-D-Z l 7 unworkcd 287 60 strokes 422 DroppingPoint ASTM-D-S66-18 132 ck. 134

The material dissolves upon contact with a sebacate ester syntheticlubricating oil (SATO 5180) at 68 F. but is too soft for holding theturbine parts during assembly. A packing composition comprising 100percent by weight of the same petrolatum, stirred, heated and set underthe same conditions was hard enough to hold parts during assembly butdid not dissolve upon contact with the same synthetic lubricating oil atthe same temperature.

EXAMPLE 2 A 30 parts by weight portion of the same petrolatum used inExample 1 is blended with 70 parts by weight of the ester of Example 1and the mixture heated to 200-250 F. with stirring for 5 minutes. At theend of this time the heating and stirring is terminated and the mixtureallowed to cool at the ambient temperature for 2 hours. The packingmaterial had the following properties.

Dropping Point Penetration ASTM-D-566-l8 ASTMD217 unworked 60 strokesEXAMPLE 3 in this example, the same heating, stirring and coolingprocedure used in Examples 1 and 2 is followed to prepare a mixturecomprising 35 parts by weight of the petrolatum of Examples 1 and 2 and65 parts by weight of the following esters of pentaerythritol.

38% by weight valerate 13% by weight 2-methyl-pentanoate 32% by weightoctanoate 17% by weight of pelargonate The consistency of the product iscomparable to a No. 1 grade grease and the product had a penetrationvalue of 310-340 using ASTM-D-217 60 stroke worked penetrationprocedure.

EXAMPLE 4 In this example the same mixing, heating, stirring and settingprocedure as well as the same quantities of components used in Example 3are employed. While the same petrolatum is used, the mixture ofpentaerythritol esters is replaced on a weight by weight basis by thesebacate ester of Examples 1 and 2. After setting the packingcomposition had a consistency comparable to No. 1 grade grease and had a60 stroke worked penetration value of 310-340 (ASTM-D-2l7 procedure).

The packing composition dissolves on contact with the syntheticlubricating oil used in Example 2 and exhibits good holding power duringassembly.

EXAMPLE 5 Three packing formulations are prepared using the samequantities of petrolatum and ester component as described in Example 4.Heating is at 200250 F. with stirring for 5 minutes and the mixture iscooled for 4 hours. After setting the compositions had comparableconsistency and penetration values to those obtained in Examples 3 and4. All three compositions dissolved upon contact with the same syntheticlubricating oil described previously and all are satisfactory for theassembly of turbine engine parts. The compositions are as follows:

Formulation 1 Formulation 2 35% by weight of a wax melting at -132F. 35%by weight ofa wax containing 2% by weight polyethylene melting at122-124 65% by weight of trimethylol propane triheptanoate 65% by weightof pentaerythritol esterified with a mixture of 1% by weight butyricacid, 92% by weight valeric acid. 4% caprylic acid, 1% by weight ofpelargonic acid and 20% by weight capric acid. The ester mixture had thefollowing vlscosity.

C.S. at 40 F- 34.38 C.S. at 210 F 380 CS. at 100 F- 17.62

Formulation 3 35% by weight ofa wax melting at F. 65% by weight oftrimethylol propane esterified with a monobasic acid mixture consistingof 2% by weight values, 9% by weight capric, 13% by weight hcptanoic, 7%by weight branched chain cctanoic, 65% by weight pelargonic acid and 1%by weight capric acids. The material had the following viscosities.

G5. at 210 F.4.29

C.S. at 100 F.l9.98

G8. at 40 F.36.38

EXAMPLE 6 A 35 parts by weight portion of petrolatum described inExamples l to 3 is combined with 62 parts by weight of thepentaerythritol ester mixture of Example 2 and 3 parts by weight oftricresyl phosphate E.P. additive. After mixing the material is heatedto 200-250 F. with stirring for 5 minutes. At the end of that time thepacking mixture is allowed to cool without stirring for 4 hours. Theresultant product is comparable in all respects to that obtained inExample 3 except that it has increased extreme pressure capabilities.

EXAMPLE 7 Each of the formulations prepared in Examples 1 to 6 areevaluated as follows:

A Timken No. 09074 Tapered Roller Bearing is packed in each of theexemplified packing formulations and spun for 30 seconds at 2,000 rpm.to determine the rapidity of softening and the ease of removal of thepacking material. In each instance approximately 20 percent of thepacking formulation splashed off and the balance became extremely softand dropped off the bearing.

A Pratt and Whitney JT30 bearing is packed in each of the exemplifiedformulations and heated for 5 minutes at 120 F. The packing softened butstill has sufficient consistency to hold the bearing in place indicatingthe suitability of the packing compositions for satisfactory performanceat high ambient temperatures. Each of the packed bearings are soaked inseparate containers of synthetic oils one primarily composed ofdi-2-ethylhexyl sebacate and the other primarily a mixture of the alkylesters of pentaerythritol. In each instance, 60 to 70 percent of thevarious packing formulations dissolved after being in contact with eachof the two synthetic oils after a relatively short time.

The above evaluation establishes the value of the inventive compositionsfor their intended purpose.

The novel dual-purpose packing compositions of this invention offersignificant advantages compared to the wholly petroleum based jelliesand thickened oils of the prior art. For example, the consistency of theunworked composition is sufficient to permit its use to hold partsduring assembly, moreover, its compatibility with turbine lubricatingoils is excellent and rapid. Complete dissolution of the packing fromthe parts into the turbine lubricating oil takes place upon workingcontact even at the relatively low temperatures encountered betweenengine startup and engine warmup. In addition the compositions aresimple to formulate and inexpensive to prepare.

As the previous discussion and illustrative examples indicate, numerouschanges and modifications in the components of the packing compositionsas well as in the conditions used to formulate them can be made withoutdeparting from the inventive concept. The metes and bounds of thisinvention are best determined by the preceding disclosure taken inconjunction with the claims which follow.

What is claimed is:

1. A dual-purpose packing composition compatible with lubricating oilsand having a consistency suitable for packing engine parts duringassembly comprising an admixture of the following components in theindicated proportions:

a. From about 30 to 50 parts by weight of a microcrystalline wax havinga melting point about 5075 C., and

b. From about 70 to 50 parts by weight of an aliphatic ester componentderived from the esterification of aliphatic alcohols, diols, polyolsand theirethers with a aliphatic acid selected from the group consistingof monoand dicarboxylic acids.

2. The composition of claim 1 wherein the alcohol has from four to 12carbon atoms.

3. The composition of claim 1 wherein the polyol is a triol.

4. The composition of claim 3 wherein the triol is trimethyolpropane.

5. The composition of claim 1 wherein the polyol is a tetrol.

6. The composition of claim 5 wherein the tetrol is pentaerythritol.

7. The composition of claim 6 wherein the pentaerythritol ester isderived from a mixture of monocarboxylic acids having from four to 12carbon atoms.

8. The composition of claim 2 wherein the ester is a sebacate ester.

9. A dual-purpose packing composition compatible upon contact withlubricating oils and capable of providing lubrication from the assemblyof jet engines to operation comprising an admixture of the followingcomponents in the indicated proportions:

a. From 35 to 45 parts by weight of microcrystalline wax having amelting point of from to F. an ASTM D 1321 penetration value of from 30to 1 l0 and a viscosity S.U.S. at 210 F. of 60.0-120,

b. From 64 to 43 parts by weight of an ester selected from the groupconsisting of the alkyl esters of sebacic acid and the fatty acid estersof pentaerythritol, wherein the alkyl groups contain from two to 10carbon atoms and the fatty acid contain from three to 25 carbon atomsand c. From 0.5 to 5 parts by weight of an extreme pressure lubricantadditive.

10. The composition of claim 9 wherein the extreme pressure lubricant istricresyl phosphate.

11. The composition of claim 10 wherein the ester is a pentaerythritolester prepared from fatty acids containing from four to 12 carbon atoms.

12. The composition of claim 10 wherein the ester is di-2- ethylhexylsebacate.

2. The composition of claim 1 wherein the alcohol has from four to 12carbon atoms.
 3. The composition of claim 1 wherein the polyol is atriol.
 4. The composition of claim 3 wherein the triol istrimethyolpropane.
 5. The composition of claim 1 wherein the polyol is atetrol.
 6. The composition of claim 5 wherein the tetrol ispentaerythritol.
 7. The composition of claim 6 wherein thepentaerythritol ester is derived from a mixture of monocarboxylic acidshaving from four to 12 carbon atoms.
 8. The composition of claim 2wherein the ester is a sebacate ester.
 9. A dual-purpose packingcomposition compatible upon contact with lubricating oils and capable ofproviding lubrication from the assembly of jet engines to operationcomprising an admixture of the following components in the indicatedproportions: a. From 35 to 45 parts by weight of microcrystalline waxhaving a melting point of from 130* to 160* F. an ASTM D 1321penetration value of from 30 to 110 and a viscosity S.U.S. at 210* F. of60.0- 120, b. From 64 to 43 parts by weight of an ester selected fromthe group consisting of the alkyl esters of sebacic acid and the fattyacid esters of pentaerythritol, wherein the alkyl groups contain fromtwo to 10 carbon atoms and the fatty acid contain from three to 25carbon atoms and c. From 0.5 to 5 parts by weight of an extreme pressurelubricant additive.
 10. The composition of claim 9 wherein the extremepressure lubricant is tricresyl phosphate.
 11. The composition of claim10 wherein the ester is a pentaerythritol ester prepared from fattyacids containing from four to 12 carbon atoms.
 12. The composition ofclaim 10 wherein the ester is di-2-ethylhexyl sebacate.